Muffler with fluid mingling and side branch chambers



June 13, 1950 w. B. MCLEOD MUFFLER WITH FLUID MINGLING AND SIDE BRANCH CHAMBERS Filed March 27, 1948 51ffrfaanalalnrlf/rfarraf.

my mw B m ..6 w Y B Patented June 13, 1950 UNITED STATES PATENT OFFICEy MUFFLER WITH FLUID MINGLING AND SIDE BRANCH CHAMBERS 2 Claims. 1

This invention relates to improvements in mufflers and may be regarded as a continuation in part of my co-pending application Serial No. 667,225, filed May 3, 1946.

An object of the present invention is to provide an improved muffler suitable for use on Diesel engines and gasoline engines wherein there is an inner shell having an inlet and an outlet and in which baiiies are suitably arranged and having an outer shell that surrounds the inner shell and which extends beyond the outlet from the inner shell. This outer shell has provision made therein for ingress of air in such a manner that air enters the outer shell adjacent the inlet to the inner shell and ows between the shells toward the outlet from the outer shell, thus mingling with the exhaust gases which issue from the outlet of the inner shell and completing their oxidation. In this manner, if the muler is mounted on an engine such as a Diesel truck, if the exhaust gases have not been completely oxidized and smoke should issue from the outlet of the muiiler proper, the completion of the oxidation of these exhaust gases before they issue from the outer shell will eliminate the objectionable smoke.

Another object of the present invention is to provide a muiiler having the above mentioned characteristics wherein the air that is admitted to the outer shell flows for a considerable distance between the shells so as to be effectively heated by the heat of the inner shell before comingling with the exhaust gases issuing from the outlet of the inner shell to thus hasten oxidation.

Still another object of the invention is to provide a construction having the above mentioned characteristics wherein the two shells are so arranged as to form a constricted passage adjacent the outlet from the inner shell so that the air on passing through this constricted passage will have a maximum velocity and thus be caused to thoroughly mix with the gases issuing from the inner shell.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a longitudinal vertical section through a muiller embodying the present invention;

Fig. 2 is a horizontal section taken substantially upon the line 2 2 lupon Fig. 1 in the direction indicated; and

Figs. 3 and 4 are longitudinal vertical sections through alternative forms of construction embodying the present invention.

Referring to the accompanying drawings wherein Similar reference characters designate similar parts throughout, and referring particularly to Figs. 1 and 2, the improved mufller may consist of an inner muffler proper, the construction of which may conform to the construction of the inner shell disclosed in my copending application. This construction, as therein illustrated, consists of an inner cylindrical shell l0 having an inlet Il and an outlet l2. Staggered bailles I3 are welded or otherwise secured to the walls of this shell and extend towards each other and toward the outlet. The inner edges of these baies are cut away or recessed, intermediate the ends thereof as indicated at i4. The inner ends of the baffles terminate short of the longitudinal central axis of the shell l0 so that there is an open or unobstructed passage between the edges of opposed baffles from the inlet it to the outlet l2. In the preferred form of construction the spacing of the opposed barles it most adjacent the inlet Il is somewhat greater than the spacing of the edges or opposed baliles near the outlet i2 so that the free or unobstructed passage from the inlet to the outlet tapers or contracts from the inlet to the outlet.

An outer shell l5 surrounds the inner shell and is disposed in spaced relation thereto. It may be held concentrically around the inner shell by spacers It arranged between the shells adjacent the outlet from the inner shell. rhe botm tom of the outer shell may be closed such as by a plate i? secured to the inlet il and, as will be observed from Fig. l, the outlet i3 from the outer shell is disposed some considerable distance above or behind the outlet l2 from the inner shell, thus providing a chamber or space iii be hind the outlet l2 in which oxidation of the exhaust gases issuing from the outlet may be completed.

Mufflers of this character, when mounted on Diesel trucks, are usually vertically positioned and the muffler has consequently been so illustrated. Provision is made for ingress of air to the space between the shells It* and I5 such as by apertures 2o that are arranged near the bottom of the outer shell i5 and on the forward side of the outer shell when considered as being vertically lnounted on a Diesel truck. The opera.- tion of the above described muffler is as follows:

The exhaust gases from the engine enter the inner shell It through the inlet II and may in the course of their passage from the inlet II to the outlet I2 expand into the pockets 2| dened by adjacent bales I3. These expanded gases may then either return to the central unobstructed passage between the inlet and outlet or they may pass through the baliles through the perforations I in progressing toward the outlet l2. The forward movement of the truck will cause air to enter the apertures 26 on the forward side of the outer shell l5 and as egress from this shell is only permitted through the outlet I8, this air is caused to ow upwardly through the space between the shells. During this upward flow the air becomes heated by the heat available from the inner shell It. In the form of construction illustrated in Fig. 1, the outer shell I5 tapers from bottom to top so that as the air passes through the passages between the spacers I5 it has a very high velocity at or near the outlet I2. This air may thus develop a turbulence in the chamber I9 and at all events becomes thoroughly mixed with the exhaust gases issuing from the outlet I2 completing oxidation of the exhaust gases in the chamber I9 and thus eliminating the smoke before the air and exhaust gases exit through the outlet I8.

In the construction illustrated in Fig. 3, there is an inner shell 25 having an inlet 26 and an outlet 2l. This inner shell is likewise equipped with bames 28 corresponding to the baliles I3. The outer shell 29 surrounds the inner shell and is held in spaced relation thereto such as by spacers Si?. The upper end of the outer shell contracts into a stack 3l, the entrance to which is disposed Very close to the outlet 2l of the inner shell to form a constricted passage 32. The air enters the outer shell through apertures 33 and on owing upwardly between the shells becomes heated and mixes with the exhaust gases issuing from the outlet 2l' in the stack 3l so that these gases are more completely oxidized before issuing from the top of the stack.

In the construction illustrated in Fig. 4, there is the inner shell that provides the muliier proper indicated at 35 and which has an outer shell 36 disposed thereabout in spaced relation thereto by means of spacers 3l. In this form of construction the upper end of the outer shell terminates in a tapered stack 33 in which the exhaust gases from the outlet of the muffler proper are more completely oxidized by the heated air that enters the outer shell through the apertures 39.

From the above described construction it will be appreciated that the improved muler not only serves to effectively silence the exhaust from the engine but provides for the completion of the oxidation of these muled gases before they issue from the outlet of the outer shell, thus eliminating objectionable smoke.

Various changes may be made in the details of construction without departing from the Spirit and scope of the invention as dened by the appended claims.

I claim:

l. A muffler adapted to be mounted upright on a truck or the lille comprising an inner cylindrical shell having an inlet and an outlet for exhaust gases, baliles on opposite sides of the inner shell spaced along the inner shell, opposed bafles being staggered with respect to one another, the ballies on both sides slanting toward the outlet and terminating short of the center of the inner shell to leave a clear straight unobstructed passageway through the inner shell, a single upright frusto-conical tube providing an outer shell in which the inner shell is positioned with its outlet end uppermost, the diameter of the outer shell at its upper end being smaller than the diameter of the inner shell and the diameter of the outer shell at its lower end being larger than the diameter of the inner shell, spacer wedges on the inner shell adjacent the outlet end thereof providing stops contacting the outer shell and positioning and locating the outlet end of the inner shell within the upper smaller end of the outer shell, the spacer wedges providing passageways communicating the space between the inner and outer shells with the space in the upper end of the outer shell, and a plate for completely closing the bottom of the outer shell and having the inlet of the inner shell passing therethrough, the outer shell having air inlets in one side only thereof located adjacent the bottom ofthe outer shell and adapted to face forwardly when the muiler is mounted on a truck or the like, that portion of the outer shell beyond the outlet of the inner shell providing a low pressure mixing chamber. the inner and outer shells `converging to restrict the ow of air just behind the outlet of the inner shell to provide a high pressure area whereby the air exiting from the high pressure area into the low pressure mixing chamber is turbulent and thoroughly mixes with and completes the oxidation of the exhaust gases exiting from the outlet of the inner shell, the exhaust gases exiting from the outlet of the inner shell being prevented by the high pressure area from passing back into the space between the outer and inner shells and being urged by the air in the high pressure area to exit through the outlet of the outer shell.

2. A muliler adapted to be mounted upright on a truck or the like comprising an inner cylindrical shell having an inlet and an outlet for exhaust gases, bailles on opposite sides of the inner shell spaced along the inner shell, opposed baies being staggered with respect to one another, the baliles on both sides slanting toward the outlet and terminating short of the center of the inner shell to leave a clear straight unobstructed passageway through the inner shell, an outer shell comprising a tube generally tapering from bottom to top and in which the inner shell is positioned with its outlet end uppermost, the diameter of the outer shell at its upper end being smaller than the diameter of the inner shell and the diameter of the outer shell at its lower end being larger than the diameter of the inner shell, means on the inner shell adjacent the outlet end thereof providing stops engaging the outer shell and positioning and locating the outlet end of the inner shell within the upper small end of the outer shell, the last named means providing passageways communicating the space between the inner and outer shells with the space in the upper end of the outer shell, and means for completely closing the bottom of the outer shell and having the inlet of the inner shell passing therethrough, the outer shell having air inlets in one side only thereof located adjacent the bottom of the outer shell and adapted to face forwardly when the muller is mounted on a truck or the like, that portion of the outer shell rbeyond the outlet of the inner shell providing a low pressure mixing chamber, the inner and outer shells converging to restrict the flow of air just behind the outlet of the inner shell to provide a high pres- Sure area whereby the air existing from the high 5 pressure area. into the low pressure mixing cham- REFERENCES CITED ber is turbulent and thoroughly mixes with and The following references are of record in the completes the oxidation of the exhaust gases exitme of this patent: ing from the outlet of the inner shell, the exhaust gases exiting from the outlet of the inner shell UNITED STATES PATENTS being prevented by the high pressure area from Number Name Date passing back into the space between the outer 1,794,276 Bowes Feb. 24, 1931 and inner shells and being urged by the air in 1,966,620 Fluor July 17, 1934 the high pressure area to exit through the outlet 2,293,632 Sauer Aug. 1,8, 1942 of the outer shell. lo 2,396,952 Huber Mar. 19, 1946 WILLIAM B. MCLEOD. 

